Moisture is a fact of life in locker rooms from high school sports through major arena sporting events. The shower room, equipment and storage areas are ripe with smells and odors from showers, damp equipment and uniforms. The smells and odors are created by molds and bacteria that are thriving in the high humidity environment of the locker room. Mold spores occur naturally in the environment. The spores proliferate on surfaces in areas of high humidity. Bacteria growth is similar. Both mold and bacteria growth can be reduced or eliminated by removing the one of the key factors needed for growth. Studies have suggested that most mold growth can be minimized by controlling relative humidity to levels below 40% RH. Modern locker rooms have utilized dry desiccant dehumidification to maintain humidity levels for the locker rooms. By reducing the moisture vapor pressure in the locker rooms, the facility and skating equipment can dry out after high activity. The low dewpoint dry air will reduce or eliminate growth of mold spores while allowing the room to dry and moisture in the equipment to evaporate. The application of a desiccant dehumidifier is appropriate to this application because of its ability to remove large amounts of water vapor form the ambient air. This provides the low vapor pressure necessary to draw moisture out of structures and equipment. By providing very dry ventilation air we can "Deep Dry" a facility to draw water out of the building, materials and equipment. Maintaining just temperature control can cause the indoor humidity to rise. Internal uses such as the showers, hot tubs and other facilities can add water vapor to elevate humidity. Current codes require increased amounts of ventilation air which must be treated properly to control humidity. ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) recommends standards that have adopted by most building codes in the United States. Typical Required Outdoor Air Ventilation Rates recommended are .5 SCFM per square foot of locker and dressing room area. As an occupied room the conditioned air can be circulated at normal conditions of 70 to 75F at 45% to 55% RH. When the room is Un Occupied the locker room and or the equipment storage area can be isolated from and outside air in the HVAC unit.

Final temperature and humidity level is always determined by environmental factors, room integrity, recirculation system and quantity of wet equipment in the space. Stage 1 describes the start of drying when the wet room is isolated for the HVAC system. This is an estimated start for the drying cycle. Stage 2 san happen rapidly based on the air change rate, equipment loading and space conditions. Stage 3 and 4 represent advanced balance between the dryer capacity and residual water in the space and equipment.

Todd Bradley, Desiccant Dehumidifier Application Specialist